The Research On High Repetition Frequency, Short Pulse-width Acousto-optic Q-switched Laser

Due to the advantages of all-solid-state, small cubage, long longevity and high pump efficiency, Q-switched diode-pumped solid-state lasers have wide applications in many fields such as laser telecommunication, remote sensing, military and medical, and have been paid much attention to. In this thesis, theoretical and experimental researches of acousto-optic Q-switch's diffraction efficiency were carried out, which educe that the diffraction efficiency is maximal within 2mm on the cross section perpendicular to the axial of the acousto-optic crystal; by using the fiber-coupled laser-diode as the pump source, Nd3+:YAG crystal as the gain medium, a acousto-optic Q-switch laser is realized. When the repetition rate is 10kHz and incident current is 1.6A, the optimal output pulse width is 16ns; on the base of the acousto-optic Q-switch experiment, Cr4+:YAG saturable absorber was inserted so that a doubly Q-switch laser is realized, and the characteristics of the pulse width were investigated. The experiment indicates that, more symmetric pulse can be obtained using the advantages of acousto-optic modulator and Cr4+:YAG saturable absorber simultaneously; whereas the doubly Q-switch experiment show that the acousto-optic Q-switch can lock the repetition frequency of output pulse, which was analyzed detailedly.